Bulldozer



Feb. 15, 1938. 5, ET AL 2,108,466

I BULLDQZER Filed Oct. 4, 1935 5 Sheets-Sheet l [N VENTOR GEO/e65 J." A 1. I. IN TH000 R FL )WN BY Z 4 4mm ATTORNEY ,19 G. s. ALLIN ET AL 2,108,466

BULLDOZER Filed Oct. 4, 1955 5 Sheets-Sheet 2 [N VEIVTOR 65024: J. HAL/Iv 26 F? F1. wwv

- BY @Wm ATTORNEY Patented Feb. s, 1938 PATENT OFFICE BULLDOZER George S. Allin, Seattle, Wash, and Theodore Patrick Flynn, Portland, Oreg.

Application October 4, 1935, Serial No. 43,518

7 Claims.

This invention relates to improvements in that class of machines known in trade as bulldozers, and it has for its principal object to provide a manually operable mechanism whereby the bulldozer blade may be raised and lowered to desired positions of use and maintained at this position until'a subsequent adjustment is made.

More specifically stated, the present invention resides in the provision of a hand wheel which is operable from the driver's or operator's platform on the tractor to control, through a rack and pinion gearing and other associated linkage, the movement of the bulldozer blade to different working elevations; also, in the provision of a brake mechanism whereby the hand wheel and the adjusting means may be held against movement afteran adjustment of the blade has been made.

Other objects of the invention reside in the details of construction, and in the combination of parts and in their mode of operation, as will hereinafter be fully described.

In accomplishing these and other objects of the invention we have provided improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, where- Fig. l is a side elevation of a bulldozer embodying the present invention.

Fig. 2 is a perspective view of the brake mechanism for holding the blade adjusting means in set positions of adjustment.

Fig. 3 is a plan or top view of the bulldozer mechanism.

Fig. 4 is a cross section on the line H in Fig.

3 looking toward the mold board.

Fig. 5 is a cross section on the line 5-5 in Fig. 4. Fig.6 is a top view illustrating the blade adjusted to an angular position. Referring more in detail to the drawings- I designates, in its entirety, what may be a tractor of any of the well known types, known as track laying tractors, and comprising a main frame structure 2 with track mounting frames 3 and 3' atopposite sides longitudinally thereof, and about which latter frames traction belts I and 4' are mounted through the mediacy of supporting wheels 5 and 6 respectively at rearward and forward ends of the tracks. Between the forward and rearward mounting wheels the tracks are functionally engaged with guide rollers Ia. which are supported from the track frames. The wheels 5 ordinarily would be the driving means for the traction belts l and 4', and these would in turn be driven by their mounting axles I, or by any other suitable means.

The track frames 3 and 3', in this instance, are pivotally supported at their rearward ends upon the opposite end portions of a transverse 5 dead axle 8 rigidly mounted in the rear part of the main frame of the tractor. The forward end of the tractor main frame is supported from the track frames through the mediacy of spring suspension means, not herein illustrated, but which 10 might be of any of the conventional types of suspension now employed.

In the present instance the bulldozer blade 9 is mounted removably upon a mold board ill. The mold board is supported forwardly of the tractor 15 and transversely thereof on the forward ends of thrust beams II and II that extend lengthwise of the tractor at opposite sides thereof and which have their rear end portions equipped with mounting brackets l2 which, respectively, are 20 pivotally mounted on the opposite ends of the dead axle 3 extended beyond the track frames, thereby to permit of an upward and downward adjustment of the forward ends of these beams, and accordingly to adjust the working elevation 25 of the blade.

Each beam H comprises a tubular rear or main portion( I la and a forward end extension portion llb telescopically fitted therein. The main portions Ila are equipped at intervals along their 30 length withtransverse slots l3, and each of the extension portions has vertical holes i4 therethrough adapted to be brought into registration with a selected slot iii of its corresponding section Ila for reception of a locking pin l5, thereby 35 to hold the position of extension of the beam and maintain a selected angular or transverse adjustment of the blade, relative to the direction of travel of the machine; various positions of adjustment being indicated in the showing of Figs. 40 3 and 6.

Upward and downward tilting of the opposite end portions of the blade is also permitted under the relative vertical movement of the track frames at opposite sides, and when such move- 45 ment takes place, there is no binding action in the telescopic sections of the thrust beams II by reason of the slots l3 being elongated in the transverse direction of the section Ila.

Each of the extension pieces Ilb is formed at 50 its forward end with vertically spaced legs l6 and I6 forming a yoke within which a knuckle I1 is pivotally mounted by a vertical bolt l8 extended through the legs l6--i6 and through the knuckle. These knuckles are of substantial vertical thick- 55 ness and in plan are in triangular form, as seen in Fig. 3, with the vertices receiving the bolts l8 and.- with their base surfaces located adjacent the mold board and disposed between horizontal ribs I 9 and I9 that are cast lengthwise of 'the mold board to strengthen it. The knuckles are secured to the mold board by vertical bolts 22 through their outside corner portions and by removable pins 23 through their inside corner portions; these bolts and pins extend through vertically alined holes in the ribs l9 and I9.

When an angular adjustment of the blade is to be made, the pins 23 are withdrawn. Then the knuckles may be swung pivotally on the mounting bolts to accommodate the setting of the blade and without effecting any spreading action or indrawing of the ends of the thrust beams I I and II. A plurality of holes are provided in the ribs l9 and [9' of the mold board to receive the pins 23 for different positions of the knuckle I1 and to lock the parts against relative movement after an adjustment has been made.

The blade 9, in the present instance, is applied against the forward, lower, longitudinal edge of the mold board I 0, and it is formed at spaced intervals along its length with rearwardly extending lugs 30 projecting through openings 3| in the lower edge of the mold board, and also projecting through openings in an angle bar 32 that is fitted to the inside of the mold board, and there are locking keys 34 driven through vertically directed openings 35 in the lugs 90 to engage against the inside face of the bar 32, thereby to lock the blade in place. To prevent displacement of the keys, their upper ends are driven through openings 31 in the horizontal flange 32a of the angle bar 32, as seen in Fig. 5, and are clinched thereover. Should it be desired to remove the blade, these pins are driven out, thereby releasing the blade lugs.

The means provided for raising and lowering the forward ends of the thrust beams II and II comprising rocker frames is as follows: overlying the forward end portion of each track frame is a triangular straddle frame structure 40 having its lower vertex pivotally attached by a horizontal bolt 4| to the track frame in a manner to permit the straddle frame to be rocked forwardly and rearwardly. Attached pivotally to the forward vertex of the triangular frame by a bolt 42 is a link 43 which, at its lower end, is pivotally atattached by a bolt 44 to a bracket 45 that is fixed rigidly to, and extended inwardly from the forward end of the adjacent thrust beam portion Ila.

Pivotally attached to the rearward vertex of the upper chord of the straddle frame by means of a pivot bolt 48 is a link 41. The two links at opposite sides of the tractor are pivotally attached at their rearward ends by means of bolts 48 to the upper ends of rocker links 49 and 49 that are fixed at their lower ends to a transverse shaft 59 revolubly supported in brackets 5| and 5|, secured on the rear end portion of the main frame of the tractor.

Associated with the mechanism at one side of the tractor, as seen in Fig. 3, is a rack bar 52 that is pivotally attached to the upper end of the corresponding rocker link 49 by the bolt 48 and extended forwardly and is supported by a roller 55 mounted on a vertical frame member 56. The teeth of the rack bar are in its upper face and meshed with a pinion gear TN A large hand wheel 88 is fixed on a horizontal shaft 8| that is revolubly supported in the frame structure 58 and onwhichshaft 8| isalsoflxedapiniongear 82 that is in driving mesh with a larger gear 88, which in turn, is fixed on the driving shaft 84 which mounts and drives the pinion gear 51. Thus, by rotation of the hand wheel in opposite directions, the rack bar 82, through the gear train described, will be shifted forwardly or rearwardly, and this will effect actuation of the blade frame supporting linkage 41, 40 and 48 to raise or to lower the blade.

Heavy coiled springs 85 are attached to the tractor frame at each side and extend forwardly and are attached under tension to the frames 48 by means of the bolts 48, thus to somewhat counterbalance the weight of the blade frame and the blade.

The links 41 comprise tubular, telescopic sections 41a and .41b provided along their lengths with holes 10, adapted to be brought into registration for reception of locking pins 1|, thereby to hold any adjustment of length made in these links.

In order that the blade may be securely held at a set position without the attention of the operator, a brake mechanism is employed, as best 11- lustrated in Figs. 2 and 3, wherein 80 designates a brake drum fixed to the axle supporting shaft 8| of the hand wheel to turn with the wheel. A brake band 8| ,is applied to the drum and this is secured at a medial point on a support 82, and the ends of the band are operatively secured to opposite ends of toggle 88 fixed on a shaft revolubly supported in standards 85 and 86. 'Two arms 81 and 88 are fixed to and extend from the shaft 84, and a coiled spring 89, supported in the frame, acts against the arm 81 thereby to rotate the shaft 84- to apply the brake and hold the hand wheel shaft against rotation. A foot pedal 99 is pivotally attached to the frame, as shown at 9|, and is connected by means of a link 92 with the lever arm 88, and this provides that downward pressure on the pedal will actuate the shaft in a direction to release the brake to permit the making of any adjustment of the blade.

With a device so constructed, it is readily apparent that, if during operation the operator desires to lift or lower the blade, he merely presses on the foot pedal 98, releasing the brake and then turns the hand wheel 68 in the proper direction -to result in the raising or the lowering of the blade. After an adjustment has been made, the foot pedal is releasedand the brake retains the adjustment.

The large springs 85 aid in lifting the blade and also absorb some of the shock that may be incident to use of the machine.

Angular adjustment of the blade is provided for in the telescopic sections of the thrust beams II and II, and a tilting action of the blade is made possible by the telescopic adjustment provided in the links 41 and 41.

Having thus described our invention, what we claim as new therein and desire to secure by Letters Patent is- 1. A bulldozencomprising, in combination, a tractor, thrust beams at opposite sides of and extended forwardly of the tractor means pivotally attaching the rear ends of said beams to the tractor, a bulldozer blade operatively mounted by the forward ends of the beams, rocker frames pivotally mounted on the tractor adjacent the forward ends of the thrust beams, links connecting the rocker frames with their corresponding thrust beams for raising or lowering the latter, a rocker shaft mounted across the rear of the tractor, lever arms fixed thereto, links connecting said arms and the rocker frames for actuthe main frame and pivotally mounting the track A ating the latter, a rack bar operatively connected with an arm of the rocker shaft, a hand wheel, a pinion gear in mesh with the rack bar and operated under control of the hand wheel to actuate the rocker shaft.

2. A bulldozer comprising, in combination, a tractor, having a. main frame and track frames at opposite sides thereof, a cross shaft fixed in frames, thrust beams at opposite sides of the tractor and pivotally mounted at their rearward ends on the said cross shaft, a bulldozer blade operatively supported by the forward ends of the beams, rocker frames pivotally mounted on the tractor adjacent the movable ends of the thrust beams, links suspending the thrust beams from the rocker frames, a rocker shaft mounted across the tractor, arms fixed to the rocker shaft, links connecting said arms with the rocker frames for control of the latter, a rack bar operatively connected with an arm of the rocker shaft, a hand wheel, a pinion gear operatively connected thereto, and meshing with the rack bar.

. 3. In a bulldozer, a tractor having a main frame and track frames at opposite sides thereof, a cross shaft pivotally mounting said track frames, a pair of thrust beams, located-at oppo-.

site sides of the tractor, with their rearward ends pivotally mounted on the ends of said cross shaft, a bulldozer blade operatively supported from the forward ends of the beams, rocker frames pivotally mounted at the forward. ends of the track frames, links suspending said beams from the rocker frames, a rockershaft mounted across the rear end of the main frame, lever arms fixed to said rocker shaft, links operatively connecting the lever arms and their rocker frames, a rocker bar operatively connected with a lever of the rocker shaft, a gear pinion meshing with the rack, a hand wheel, a supporting shaft for the hand wheel,a brake drum fixed on said shaft,

a brake band fitted to the drum, yieldable means holding the band applied, and a foot pedal operativcly connected with the band for releasing its hold on the drum.

4. A device as in claim 3 wherein said thrust beams comprise telescopically adjustable parts for extending or reducing their lengths. 5. A blade mounting comprising, in combination, a pair of thrust beams fixed in parallel relation and independently, longitudinally movable, a blade support,.a knuckle pivotally mounted by a vertical pivot pin at the forward end of each beam; said knuckles having pivotal connection, respectively by vertical pivot pins, with the oppcsite ends of the blade support permitting an gular adjustment of the blade relative to the beams, without disturbing parallel relation of the thrust beams, and means for fixing the knuckles against movement in their connection with the blade support after an angular adjustment of the blade has been made.

l 6. In combination, a pair of th ust beams fixed in parallel relation and longitudinally adjustable relative to each other, a blade supporting mold board, connecting knucklesinterposed between the forward ends of the said beams and the ends of the mold board, said knuckles being of triangular form, vertical pivot pins connecting the apex ends of said knuckles to the for-' ward ends of said beams and vertical pivot pins connecting the knuckles through one of their other corners to the mold board respectively at opposite ends to permit of angular adjustment of the blade by relative longitudinal adjustment of the beams; each of said knuckles having a vertical aperture through its other comer and said mold board having a series of apertures with which said knuckle aperture may be registered for different angular positions of the blade, and locking pins extended through the registered anertures of the kniickles and mold board.

'I. A mold board having means of support at its ends, a blade fitted to the front face of the mold board; said mold board having apertures therethrough and said blade having lugs extended through said apertures, and tapered locking keys engaged with said lugs and back face of the a 

